Spraying Expands in New York Encephalitis Fight

By JODI WILGOREN

Published: September 10, 1999

Correction Appended

New York City vastly expanded its week-old air raid on mosquitoes yesterday with pesticide spraying scheduled over the next three days for all of Brooklyn and Queens and much of the Bronx, as the number of suspected cases of the potentially deadly St. Louis encephalitis grew to 60, including, for the first time, 3 residents of Manhattan.

Mayor Rudolph W. Giuliani said that ground spraying of malathion, which kills mosquitoes, was planned for most of Manhattan in the coming days, and that the aerial assault would continue until the first frost, probably at least a month away, over the rest of the city, including Staten Island.

Air spraying is impractical in Manhattan because of the density of the buildings and the evening crowds outdoors, officials said.

''I ask you not to create any undue or unnecessary alarm or panic,'' Mr. Giuliani said at a news conference yesterday morning at City Hall. ''There's no point in not spraying, because there's no harm in spraying. So even if we're overdoing it, there's no risk to anyone in overdoing it.''

''The more dead mosquitoes,'' he added, ''the better.''

Roger S. Nasci, a research entomologist at the Centers for Disease Control and Prevention, said the current outbreak -- with 9 confirmed cases, 3 of them fatal -- ranks among the smaller incidences of St. Louis encephalitis, which infected about 2,200 people throughout the Mississippi Valley in 1975. But he said that this epidemic presented a special challenge.

''Given that this is New York City, you have a very large population at risk,'' said Dr. Nasci, who is assisting local officials in fighting the disease. ''That's the reason for this very aggressive aerial spray approach to control the mosquitoes.''

City officials said they would not name the victims, to protect their privacy.

Spraying will take place only when mosquitoes tend to be active, from about 5 to 10 P.M. and from about 4 to 8 A.M., city officials said. Last night, the spraying began in parts of Queens and the Bronx but was aborted because of heavy rain.

This morning, three helicopters were scheduled to spray malathion throughout much of Brooklyn, from Prospect Park on south to the water; in the Bronx, between the Bronx River Parkway and the Hutchinson River Parkway, and in Queens, from Bay Terrace south to Hollis Hill and east to the Nassau County line. Tonight, the spraying is to continue in northern Brooklyn, and tomorrow, the city plans to hit the rest of eastern Queens and the northern Bronx, though the entire schedule is subject to change according to the weather.

In addition to the spraying, officials from the State Department of Health and the C.D.C. planned to spread 24 traps around the city so they can monitor mosquito levels and track the virus. Workers from the police, fire, housing and transit departments were also canvassing neighborhoods in Brooklyn and Queens to warn people of the problem and distribute cans of insect repellent.

''We're moving as quickly as we can to both inform and to get this activity going,'' said Sandra Mullen, a spokeswoman for the City Health Department.

City officials suggested that residents remain indoors during the spraying, but asserted that malathion is not dangerous, though it can cause some problems for people with respiratory illnesses. In other states where malathion has been used, officials have warned residents to cover their cars during spraying or rinse them afterward because protein-based bait that is mixed into the spray can damage the paint.

New York City officials urged people to use insect repellent outdoors between dawn and dusk and to open only windows with screens.

''It's basically an individual's responsibility at this point to protect themselves,'' said Jonathan F. Day, a professor of medical entomology at the University of Florida, who specializes in St. Louis encephalitis. ''What I would do is avoid getting bitten at night.''

The major expansion in the spraying campaign came the day after an 80-year-old resident of Sunset Park, Brooklyn, died from the virus, and three other cases were confirmed in eastern and central Queens, several miles from the original epicenter of the epidemic, near Whitestone and College Point.

The virus was first confirmed on Sept. 2, and the spraying began the next day. The first two deaths came last week, on Tuesday and Thursday, at Flushing Hospital Medical Center.

By Tuesday, the number of confirmed cases had grown to six. On Wednesday, it was nine.

Officials are still awaiting lab results from about 60 patients to determine whether they actually have the disease, and hospitals throughout the region are closely monitoring people who complain of symptoms ranging from persistent high fevers to severe headaches, slurred speech, blurred vision and nervous tics.

''The majority of the calls that we're getting, we have a very low index of suspicion,'' said Dr. Neal L. Cohen, the City Health Commissioner. ''There is still a relatively small number of people that we have a stronger suspicion of St. Louis encephalitis.''

Fear spread along with the spraying yesterday afternoon.

''I'm leaving; I'm going to Nantucket,'' said Penny Dow, 39, who takes her son, Gabriel, to Riverside Park every afternoon. ''All you need is one mosquito to bite your kid.''

Correction: September 11, 1999, Saturday An article yesterday about the expansion of mosquito spraying in New York City to combat an outbreak of St. Louis encephalitis misstated the home borough of the third person to die of the disease. It was Queens, not Brooklyn. (Officials said Wednesday that they had confirmed a case of St. Louis encephalitis in a man from Borough Park, Brooklyn, but he has not died.) The article also misstated the number of possible cases in Manhattan and the times they were reported. Mayor Rudolph W. Giuliani said yesterday that at least four possible cases of encephalitis had already been identified in Manhattan through Sunday; three possible cases were not reported on Wednesday for the first time. In addition, the article misstated the time of day for people to use insect repellent while outdoors. It is from dusk to dawn, not the reverse.